Silicon Self-Diffusion in Quartz

Abstract

${}^{30}\mathrm{Si}$ diffusion was measured in quartz along c axis in the $\ensuremath{\beta}$-phase field, at $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1400$-- $1600\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ by Rutherford backscattering spectrometry and the ${}^{30}\mathrm{Si}(p,\ensuremath{\gamma})^{31}P$ resonant nuclear reaction. The diffusion coefficient $D({\mathrm{cm}}^{2}{\mathrm{s}}^{\ensuremath{-}1}){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}10}^{(6.1\ifmmode\pm\else\textpm\fi{}2.7)}\mathrm{exp}[(\ensuremath{-}7.6\ifmmode\pm\else\textpm\fi{}1\mathrm{eV})/\mathrm{kT}]$, comparable to $D$ of silicon in vitreous ${\mathrm{SiO}}_{2}$. We suggest Frenkel pairs as majority defects with diffusion occurring by interstitial mechanism.